This is quite the project, that requires time, and money. you have to build a full area wherethe tiles will sit. this can be constructed using mdf, plywood anything really. but within the "sidewalk" you need tiles. i suggest thick plexi glass sanded. obviously under that a form of light, as suggested below a LED array would best fit what your trying to achieve. now the tils should be on springs that when stepped on will lower and conect the connection, very much like the way a DDR pad works, fortunately tons of people have written tutorials as to how to build them. Here is just one for example:

read about how they make the switches for there feet. connect this to a 12v connectio and the led array and boom theres your touch switch. But do a little more research on the Dance Dance Revolution builds and you should find a decent way of building these switches. besides that mechanics of the switches, i feel the rest is just wood working, or construction skills, dang i wish you lived closer so i could help :) hope this gives you an idea as to what needs to be done. one major project.

so i have no idea what the answer is... but i did see an interview with the director of the music video recently, and it sounded like the lights lit in a particular pattern, and the dancing was choreographed around them, not the other way around!

put the tiles on springs strong enough to support the weight of the tile then put switches that are depressed (ha, emo electronics) and complete an led circuit....or use a PVDF sensor as steveastrouk said...

I did some years back using PVDF sensors to detect a "change" in weight on a tile, rather than the absolute weight. PVDF is a piezoelectric plastic and can be bought very cheaply. THe output voltagefrom the sensor is high enough to be easy to amplify with a very simple circuit, then used to trigger a TRIAC to power a light.
Steve